1. Field of the Invention
The present invention relates generally to virtualization. More specifically, the present invention relates to techniques for efficient placement decisions in virtualization environments having heterogeneous storage and network connectivity.
2. Description of Background
Virtualization is, broadly speaking, the ability to make computing resources abstract. Diverse computing resources can be made abstract through virtualization. Notably, platform virtualization is the virtualization of computer systems (as opposed to, for example, storage or computer networks).
Common types of platform virtualization include full virtualization and operating system-level virtualization. Full virtualization is the execution of multiple operating system instances (OSI's) on a single computer. The OSI's are usually isolated from each other despite their coexistence within the same computer. By contrast, operating system-level virtualization is the presentation of multiple spaces within a single operating system. Programs execute within the spaces thus presented. The spaces are isolated from each other despite their coexistence within the same operating system.
Virtualization technologies have existed for a significant period of time. For example, the IBM® VM product line, which implements virtualization, was originally announced in 1972. IBM is a registered trademark of International Business Machines Corporation, Armonk, N.Y., United States, in the United States, other countries, or both.
However, virtualization technologies have recently been experiencing increased usage as well as changing usage patterns. Virtualization originated on hardware which was among the most powerful available at that time. By contrast, at the time of this writing, virtualization is becoming increasingly prevalent on less powerful hardware as well. Several factors are contributing to this trend. One such factor is that, at the time of this writing, virtualization technology is either free or cost-effective. As a result, virtualization is within the reach of potentially every customer and organization. Moreover, modern virtualization systems are increasingly flexible and easy to use. This ensures that the small army of highly-trained support personnel which was formerly required to maintain virtualization systems is no longer necessary. Thus, the increasing prevalence of virtualization on less powerful hardware is having a marked effect on the Information Technology (IT) industry.